Heat economizer for condensing prime movers



Aug. 4, 1925.

W. D. DRYSDALE ET AL HEAT ECONOMIZER FOR CONDENSING PRIMEv MOVERS 2 Sheets-Sheet 1 0000000000 OOOOOOOOOOOOOO .OOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOO JvJ-ECTOP? Aug` 4, 1925.

. 1,548,585 W. D. DRYSDALEV ET AL HEAT EcoNoMIzER FOR coNDENsING PRIME MovERs Filed Oct. 15, 1919 2 sheets-sheet 2 *i Q v Q y M gwn/,Mou

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aummup Patented Aug. 4, 1925.

UNITED STATES VJAIITER D. DRYSDALE AND ALEX DOW, 0F DETROIT, MICHIGAN.

HEAT ECONOMIZER FOR CONDENSING PRIME MOVERS.

Application filed October 1.5, 1919. Serial No. 330,782.

1o all 107mm t may concern.'

Be it known that we, WALTER D. Dars- DALE and ALEX Dow, both citizens of the United States of America, residing at Detroit, in the county of Wayne and State. of Michigan, have invented certain new and useful Improvements in Heat Economizers for Condensing Prime Movers, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to heat econ'omizers for condensing prime movers, and its object is to save the heat in the drip discharge from a prime mover of this type.

It is essential to provide the different pressure stages of a condensing prime mover (such as the successive cylinders of a condensing steam engine, or the different stages of a condensing steam turbine) with drips to get rid of the water which, if allowed to accumulate, would interfere with the moving parts of the prime mover, but it is usually necessary to allow some steam to escape at the same time, 'which is especially true when the pressure in the pressure stage is, below the atmospheric pressure. The drip system of a large prime mover, if equipped with steam traps throughout, becomes very much complicated and if any of these traps cease to function, a serious accident may arise through accumulation of the water.

Heretofore, drips from pressure stages in which the pressures are below that of the atmosphere have been connected directly to the condenser through restricted openings, thereby permitting a small constant iiow of mixed water and steam and keeping the pressure stages free of any accumulation of water. The sensible heat of the mixture of steam and water forming the drip charge and the latent heat of steam is lost when it is discharged into the condenser, because it is transferred to the circulating water of the condenser and thus thrown away. To avoid this loss the drips are sometimes led to a vaporizer or to an auxiliary condenser system, or some equivalent device, whereby the heat of the drip discharge is transferred l to the feed water on its way to the boilers.

The use of such a system, however, becomes as complicated as the use of a multiplicity of steam traps and it has not the advantage of being a self-contained part of the condensing prime mover operating only when the prime mover is in service.

With our invention the sensible heat of the mixture of steam and water and the latent heat of steam is saved, and furthermore the system is a self-contained part of the condensing p-rime mover, which operates only when the prime mover is in operation.

Other objects of the invention reside in further advantages as more fully hereinafter set forth.

In the drawings:

Figure l is a side elevation partly in section of a condensing prime mover embodying our invention;

Figure 2 is a side elevation showing a portion of a modified construction;

Figure 3 is a top plan view showing a portion of still another modified construction;

Figure 4.- s a cross section on line l-4 of Figure 3. v

Figure 5 is a cross section on the line 5 5 of Figure l.

Our' invention is particularly applicable to condensing prime movers using surface condensers wherein the condensate (that is to say, the water formed by the condensation ofsteam after its passage through the condensing prime mover) accumulates in the bottom of the condenser or in an eX- tension thereof, commonly known as a hot well. This condensation is in most cases three to ten degrees colder than vthe temperature of re-evaporation corresponding to the pressure within the condenser, but the effort of operators is to have its temperature as high` as possible and preferably at the upper limit.

In general, our invention consists of arrangements and devices whereby the drip discharge from the condensing prime mover can be mixed with the condensate and the whole heat of the drip discharge thereby saved. Inasmuch as the condensate is used as feed water in the boilers whatever eXtra heat is put into it before its arrival at the boilers saves adding the same amount of heat in the boilers by the burning of more coal. It is obvious that if the heat added by the drip discharge raises the upper portion of the condensate above the re-evaporation temperature the vapor thus released will be condensed by the circulating water in the condenser and the heat thereby lost.

llt)

` bine and 7 is a hotWell at the bottom of the condenser for receiving the condensate. 8 is a pump for withdrawing the condensate 'from the hotvv'ell 7 through the discharge opening 9 located near the bottom .of the hot Well. 10 are `drips connecting into the pressure stages 2, 3 and 1,the function of these drips being to tree the pressurestages or' the Water therein. Steam as Well as 'vvaterimay pass throughV these: drips, theipurposeoif the steam being to eject the Water `from *the `pressurestages. l

In order to savethe heat in the discharge passing through the drips 10, and in order to maire the systemv a self-.contained part of the turbine Which operates only When the turbine is in. operation, the *following ccnstruction is. provided: 11is a pipe which communicates `with suitable pipe connections 12. leading from the drips 10. This pipe 11 entendsinto the hot well? and'is provided with a Vsuitable injector 13 at its end Within the. hot Well. `The "longitudinal axis of the injector is substantially parallel to the direction cffiovv "oi the condensate leading to the discharge opening 9 in the hot Wel-l so that thepdirectionof flow of the `drip i discharge is the same as that `of the condensate `Furthermore, the injector 13 entends adjacent tothe discharge opening 9 and near the bottom `ofthe hot Well so that the drip discharge WillV mix With only a limited `amount" of the condensate in the hot Well `before passing through the discharge opening, the remainingpart of thecondensate inthe hot `Well not being heated. As

shovvn, theinjector is provided with aperf j Y vrangement which 1s a selicontained part tures 14' in the periphery of its spherical enlargement, Whcih permit of the passage of a limited amount oil' condensate into` the injector to mix Withy the mixture of Water and steam passing from the drips 10.

From the above description it is seen that the drip discharge is delivered into the condensateV in the hot Well Vunder the surface; of the condensate andpreferably near theA bottomof the hot Well, so that thestatie pressureof the condensate above the point of entrance ot the drip discharge will tend to prevent reevaporation. Further, the entrance of the drip dischargeV is so located and directed that it givill facilitate the motion of the condensate toward its discharge v openingfin the hot Well, thereby tending to revent the rise ofthe condensate heated y the drip discharge towards the freesur-V face of the remainlng condensate.

As shown 1n the modified construction in "the condensate.

"being at a lower level than the hot Well and,

being connectedto the discharge opening in the hot Well by means of the pipe connectionV 17. With this arrangement the static pressure of the condensate abovethe point of .delivery of the drip discharge Vinthe condensate is increased soy that the re-evaporation temperature of the condensate at this lower lever is correspondingly greater.

With this arrangement it is possible to run the condenser to closer temperature limits.

VWith the construction as shown in Figures 3 and {1,two hot Wells 18 as vvell as two pumpsfl@ are provided for takingcare of into achamber 2O AWhieh'is connected with the pumps 19 so that either` or both pumps may Withdraw the condensate therefro`m-`V Vit-h `this construction it would be detri.-

mental to arrange the discharge Aend of the in such a Way as to secure adirectional flows `toward either pump. By` our arrangement The 4hot Wells discharge We have provided means forydelivering they i drip discharge into the chamber 2O insuch -a vvay as Vto assist either or both pumps `properly Withdravvingthe condensate, or at least in such a Way. that the deliveryoi the drip'discharge Will not havea `detrimental effectupon the pumps. Specifically, Qlwisfa V pipeleading from. the drips of the turbine and 22 `is the 'injector' atfthe end of the pipe 21 and Within the chamber 20, this injec-` tor being Ilocatedintermediate thel pumps 19 and sol arrangedthat the dripl discharge produces a vortex flow inthe chamber V20,

the: latter being preferably cylindrical Vin j shape.

" From the above description it Willdbe i readily seen that We have 'devised an arof the turbine andV which automatically op o crates only when the turbine is in operai tion. Moreovenxthe heat of the drip discharge from the pressure stages of the VturF i bine is savedby mining the drip discharge with the condensate. Furtheig by our particular `method of deliveringthe drip disj-` charge into the condensate only a limited portion of `the latter is heated and this is Withdrawn from the hot Well before it can rise to the surface of the condensate and cause are-evaporation. i v

What We claim as our invention 1s:

'1. `The method of saving the heat in the` surface of the latter and the using of the condensate as boiler feed Water. Y

2. `The method of savingV the heat in the icc drip discharge of the condensing prime mover, which comprises the. delivery of the drip discharge into the condensate in the line of motion of the condensate toward its point of discharge and the use of the condensate as boiler feed water.

3. The method of saving the heat in the mixture of water and steam drained from a pressure stage of a condensing prime mover, which comprises the delivery of the mixture of water and steam into the con densate in such a manner that the mixture of water and steam facilitates the motion of the condensate toward a point of discharge and also comprises the use of the condensate as boiler feed water.

4f. The method of saving the heat in a drip discharge of a condensing prime mover, which comprises mixing the drip discharge with a limited amount of the condensate below the level of the latter and using the condensate as boiler feed water.

5. The method of saving the heat in a drip discharge of a condensing prime mover, which comprises the delivery of the drip discharge into the condensate in such a manner that that portion of the condensate heated by the drip discharge and also the drip discharge will be drawn from the remaining 'portion of the condensate before the latter is heated and also comprises the use of the condensate as boiler feed water,

6. In a heat economizer for steam prime movers, the combination with a drip connection for a pressure stage of the prime mover, a condenser for the exhaust steam from said prime mover, and a reservoir for the condensate having a discharge opening, of means for conducting the drip discharge from said connection into said reservoir and adjacent to said discharge opening, said condensate being used as boiler feed water.

7. The method of saving the heat in the drip discharge of a condensing prime mover, which comprises the mixing of the dripI discharge with the condensate and maintaining a liquid seal between the point of mixing and the surface of the condensate exposed to the condenser and also comprises the using of the condensate as boiler feed water.

8. The method of saving the heat in the drip discharge of a condensing prime mover, which comprises mixing the drip discharge with the condensate and maintaining a liquid seal between the point of mixing and the surface of the condensate exposed to the condenser, thereby raising the temperature of the condensate, and using the heated condensate for a purpose where the available heat of said condensate is beneficial.

9. In a heat economizer, for steam prime movers, the combination with a drip for a pressure stage of the prime mover, a condenser for the exhaust steam from said prime mover, and a reservoir for the condensate, of means for conducting the drip discharge from said drip into said reservoir, and means for maintaining a liquid seal between the point of delivery of said drip discharge into said reservoir and the surface of the condensate exposed to the condenser, said condensate being used for a purpose where the available heat therein is beneficial.

l0. The method of saving the heat in the drip discharge of a prime mover connected with a condenser, which comprises the delivering of the drip discharge without substantial change in its condition directly into the condensate formed by said condenser, withdrawing a mixture of condensate and drip discharge, and utilizing said mixture for a purpose where the available heat stored in said discharge is beneficial.

ll. The method of saving the heat in the drip discharge of a condensing prime mover, which comprises the delivery of the drip discharge without substantial change in its condition i directly into the condensate formed by said condenser, mixing said discharge with a portion of the condensate to raise the temperature of the latter, and withdrawing the condensate heated by said drip discharge, and utilizing the same for purpose where a preheated liquid is benecial.

12. The Vmethod of saving the heat in the n drip discharge of a condensing prime mover,

which comprises the mixing of the drip discharge with the condensate, maintaining a liquid column between the point of mixing and the condenser, and utilizing the condensate heated by said drip discharge for a purpose where a heated liquid is beneficial.

13. In a heat economizeifor steam prime movers, the combination with a drip for a pressure stage of the prime mover, a condenser for the exhaust steam from. said prime mover, and a reservoir for the condensate, of means for conducting the drip discharge from said drip into said reservoir below the surface of the liquid therein, and means for withdrawing from the reservoir the liquid containing the heat of said drip discharge.

In testimony whereof we afiix our signatures.

VVALTER D. DRYSDALE.

f ALEX DOV. 

